CN103334769A - Cross building block wall supporting method for reinforcing empty roadway of advanced working face - Google Patents

Abstract

A cross block wall support method for reinforcing an empty lane of an advanced working face. When the working face passes through an empty lane, a cross block wall is built in the empty lane for reinforcement. The cross block wall is composed of a main wall and an auxiliary wall. The distance between adjacent cross block walls is determined by calculating the support resistance borne by the cross block wall. According to the situation of the basic top breaking above the working face, the empty lane support resistance to prevent the basic top breaking rock block from becoming unstable is calculated. The obtained empty lane support resistance is multiplied by the surplus coefficient 1.5 to calculate the support resistance borne by the cross block wall. From this, the distance between adjacent cross block walls can be obtained, and the empty lane can be supported by building a cross block wall with aerated concrete blocks. This method has simple process, convenient construction, and easy operation. When the working face passes through an empty lane, the coal mining machine can directly cut the cross block wall, which is convenient for recovering the original I-beam shed support in the empty lane, reducing the recovery work and its unsafe factors.

Description

Cross-block wall support method for strengthening the empty roadway of the advanced working face

technical field

The invention relates to a wall body support method, in particular to a cross block wall body support method suitable for strengthening the empty roadway of an advanced working face in underground coal mines.

Background technique

With the continuous increase of mine coal mining intensity, mine resources are gradually exhausted, and further improving the recovery rate of coal resources has become an important issue for high, stable and sustainable mine production. Among them, the mining recovery of residual coal pillars is an important content in the recovery of coal resources. Due to the change of coal seam occurrence conditions, the recovery of a large number of residual coal pillar resources left after regular mining and block arrangement has gradually become an urgent problem to be solved to maintain stable and high production in the middle and late stages of large mines.

In the process of recovering residual coal pillars, it is often encountered that the working face passes through the gob. During the process of the working face passing through the gob, as the working face advances, the width of the coal pillar between the working face and the gob gradually decreases. Under the action of the advanced support pressure, the narrow coal pillars are broken and unstable, and the length of the empty roof of the basic roof increases. Among them, during the process of the working face passing through the gob, the rock block B is very easy to lose stability, causing the gob and the roof of the working face to sink sharply, and the mine pressure is severe.

I-shaped steel sheds are generally used for support in the empty alley, which brings great inconvenience to the recovery work when the working face passes through the empty alley

To sum up, the existing technology is passive and dangerous for the safe passage of gobs in the working face, which greatly limits the recovery of such coal pillars, reduces the coal recovery rate, causes waste of resources, and does not meet the safety and efficiency requirements of mines. production principles.

Contents of the invention

Technical problem: The purpose of this invention is to provide a cross block for strengthening the goblin of the leading working face, which is easy to operate, safe to protect the roof, and can improve the coal recovery rate. Wall support.

Technical solution: The cross-block wall support method for reinforcing the empty roadway of the advanced working face according to the present invention is characterized in that it includes the following steps:

a. According to the overlying condition of the surrounding rock above the gob in the working face, lay out multiple cross block walls, and first analyze the hinged structural rock blocks A, B, and C formed by the breaking of the basic roof above the coal mining face, among which The length l of the rock block B is the working face period to press the step distance; by the formula:

The minimum gob support resistance P ₁ to prevent rock block B from destabilizing is obtained;

b. Multiply the obtained minimum support resistance P ₁ of the gondola by the adequacy factor 1.5 to obtain the support resistance P borne by the cross block wall;

c. Set the compressive strength of the cross block wall in the working face cavity to 25MPa, and the ratio of the length of the main wall of the cross block wall to a ₁ and the width to b ₁ is a ₁ :b ₁ =5:3 , the ratio a ₂ of the length a ₂ of the auxiliary wall to the width b ₂ : b ₂ is 4:3; if the width of the alley is d ₁ , the width b ₁ of the main wall is 0.4d, and the length a ₂ of the auxiliary wall is 0.3d;

d. Set the distance between adjacent cross block walls as L, the cross-sectional area of cross block walls as S, and calculate the distance L between adjacent cross block walls by the following formula:

P=1.5×P ₁

S＝a ₁ ×b ₁ +2×a ₂ ×b ₂

$\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 25</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; S</span>}}{\mathrm{<span\; class="notranslate">\; P</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="d"\; filenames="DEST\_PATH\_EDA00003360976400011.png"\; state="\{\{state\}\}">d</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}$

为岩块间的摩擦因数；十字砌块墙体的主墙长度为a₁、宽度为b₁,辅助墙长度a₂、宽度b₂；空巷宽为d₁；Among them: q is the dead weight per unit length of the rock block B and its upper weak rock layer; h is the thickness of the basic top; l is the length of the rock block B; θ is the rotation angle of the rock block B; a is the rock block B and the rock block A, The _contact height of C; _the calculation formula a=(h-lsinθ)/2; q ₀ is the self-weight per unit length of the direct top; _A =T _B , T _A =ql/hl-12sinθ; P ₁ is the support resistance of the goaf, P ₂ is the support resistance of the working face, where the resultant force of P ₁ acts on b/2, and the resultant force of P ₂ acts on d/3; where, b and d are the width of the goaf and the supporting roof of the working face respectively;

is the friction factor between rock blocks; the length of the main wall of the cross block wall is a ₁ , the width is b ₁ , the length of the auxiliary wall is a ₂ , and the width is b ₂ ; the width of the open road is d ₁ ;

e. According to the size of the cross block wall set above and the calculated distance between two adjacent cross block walls, the cross block wall is built with aerated concrete blocks for construction to support the empty alley. protect.

Beneficial effects: due to the adoption of the above-mentioned technical scheme, the present invention can enable the working face to pass through the goaf safely, quickly and effectively, avoiding the use of I-shaped steel shed support for the gob in the traditional method, and the working face passing through the gob. The inconvenience caused by the recycling of the I-beam shed and the safety hazards in the recycling work. During the process of the working face passing through the goaf, a cross block wall is built in the goat for reinforcement. The cross block wall is composed of the main wall and the auxiliary wall, the compressive strength is 25MPa, and the length-to-width ratio of the main wall is 5:3 , the aspect ratio of the auxiliary wall is 4:3, the width of the main wall is 0.4 times of the width of the alley, and the length of the auxiliary wall is 0.3 times of the width of the alley. The distance between adjacent cross block walls is determined by calculating the supporting resistance borne by the cross block walls. According to the breakage of the basic roof above the working face, calculate the goblet support resistance to prevent the instability of the broken rock block of the basic roof, and multiply the calculated gob support resistance by a surplus coefficient of 1.5 to calculate the cross block wall. Supporting resistance, from which the distance between adjacent cross block walls can be obtained, and the empty lane can be supported by building cross block walls with aerated concrete blocks for construction. This method is simple in process, convenient in construction, and easy to operate. When the working face passes through the goaf, the shearer can directly cut the cross block wall, which is convenient for recycling the original I-shaped steel shed support in the goaf, and reduces the recovery work and unsafe factors. , has wide applicability.

Description of drawings

Figure 1 is a schematic diagram of the breaking characteristics of the basic roof above the goaf;

Fig. 2 is a schematic diagram of the mechanical model of the surrounding rock structure of the gob;

Fig. 3 is a schematic diagram of a cross block wall model of the present invention.

In the figure: 1-main wall; 2-auxiliary wall; A, B, C-basic roof broken rock block, D-direct roof, E-coal pillar, F-gob road, G-working face, H-goaf , a—contact height between rock block B and rock blocks A and C, b—width of gob support control roof, σ _c —compressive strength of rock block, d—width of working face support control roof, l—rock block The length of B, q ₀ —the self-weight of the unit length of the direct top, q—the self-weight of the unit length of the rock block B and its upper weak rock formation, P ₁ —the support resistance of the gob, P ₂ —the support resistance of the working face, T _A , T _B —horizontal thrust of rock block B at its two ends, θ—rotation angle of rock block B; a ₁ , b ₁ are the length and width of the main wall of the cross block wall; a ₂ , b ₂ cross block wall The length and width of the auxiliary wall; the width of the alley is d ₁ .

Detailed ways

An embodiment of the present invention will be further described below in conjunction with accompanying drawing:

The method for supporting the cross block wall body of the present invention for strengthening the empty roadway of the advanced working face, the specific steps are as follows:

a. According to the geological prospecting results of the overlying surrounding rock above the working face gob, a plurality of cross block walls composed of the main wall 1 and the auxiliary wall 2 are arranged in the gob F, and the upper part of the coal mining face G is first laid. The broken rock blocks A, B, and C of the basic roof are analyzed, and at the same time combined with the specific spatial position of the goaf H and the coal pillar E and the broken condition of the direct roof D, the broken condition of the basic roof is analyzed. The length of the rock block B is l Press the step distance for the face cycle; by the formula:

The minimum gob support resistance P ₁ that should prevent rock block B from destabilizing is obtained, such as P ₁ =0.5MPa;

b. Multiply the obtained minimum support resistance P ₁ of the gondola by the adequacy coefficient 1.5 to obtain the support resistance P=0.75Mpa borne by the cross block wall;

c. Set the compressive strength of the cross block wall in the working face cavity to 25MPa, the length of the main wall of the cross block wall is a ₁ =2m, the width b ₁ =1.2m, a ₁ :b ₁ =5 :3, auxiliary wall length a ₂ =0.9m, width b ₂ =0.675m, a ₂ :b ₂ is 4:3; empty lane width d ₁ is 3m, then main wall width b ₁ is 0.4d ₁ =1.2m , the auxiliary wall length a ₂ is 0.3d ₁ =0.9m;

d. Set the distance between adjacent cross block walls as L, the cross-sectional area of cross block walls as S, and calculate the distance L between adjacent cross block walls by the following formula:

P=1.5×P ₁

S＝a ₁ ×b ₁ +2×a ₂ ×b ₂

$\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 25</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; S</span>}}{\mathrm{<span\; class="notranslate">\; P</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="d"\; filenames="DEST\_PATH\_EDA00003360976400011.png"\; state="\{\{state\}\}">d</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 40.17</span>}\mathrm{<span\; class="notranslate">\; m</span>}$

为岩块间的摩擦因数；a₁、b₁十字砌块墙体的主墙1长与宽；a₂、b₂十字砌块墙体的辅助墙2长与宽；空巷宽为d₁。Among them: q is the dead weight per unit length of the rock block B and its upper weak rock layer; h is the thickness of the basic top; l is the length of the rock block B; θ is the rotation angle of the rock block B; a is the rock block B and the rock block A, The _contact height of C; _the calculation formula a=(h-lsinθ)/2; q ₀ is the self-weight per unit length of the direct top; _A =T _B , T _A =ql/hl-12sinθ; P ₁ is the support resistance of the goaf, P ₂ is the support resistance of the working face, where the resultant force of P ₁ acts on b/2, and the resultant force of P ₂ acts on d/3; where, b and d are the width of the goaf and the supporting roof of the working face respectively;

is the _friction factor between rock blocks; the length and width of main wall 1 of a ₁ and b ₁ cross block walls; the length and width of auxiliary wall 2 of a ₂ and b ₂ cross block walls; .

e. According to the size of the cross block wall calculated above and the distance between two adjacent cross block walls, the cross block wall is built with aerated concrete blocks for construction to support the empty alley.

Claims (1)

1. a cross block wall support method for reinforcing the empty roadway of the leading working face, is characterized in that, comprises the steps: a. According to the overlying condition of the surrounding rock above the gob in the working face, lay out multiple cross block walls, and first analyze the hinged structural rock blocks A, B, and C formed by the breaking of the basic roof above the coal mining face, among which The length l of the rock block B is the working face period to press the step distance; by the formula:

The minimum gob support resistance P ₁ to prevent rock block B from destabilizing is obtained; b. Multiply the obtained minimum support resistance P ₁ of the gondola by the adequacy factor 1.5 to obtain the support resistance P borne by the cross block wall; c. Set the compressive strength of the cross block wall in the working face cavity to 25MPa, the length of the main wall (1) of the cross block wall is a ₁ , and the ratio of width to b ₁ is a ₁ : b ₁ =5:3, the ratio a 2 of the length a ₂ and width b ₂ of the auxiliary wall ( ₂ ): b ₂ is 4:3; record the width of the alley as d ₁ , then the width of the main wall b ₁ is 0.4d ₁ , the auxiliary The wall length a ₂ is 0.3d ₁ ; d. Set the distance between adjacent cross block walls as L, the cross-sectional area of cross block walls as S, and calculate the distance L between adjacent cross block walls by the following formula:

P=1.5×P ₁ S＝a ₁ ×b ₁ +2×a ₂ ×b ₂ $\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 25</span>}<span\; class="notranslate">\; \&times;</span>\mathrm{<span\; class="notranslate">\; S</span>}}{\mathrm{<span\; class="notranslate">\; P</span>}<span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}$ Among them: q is the dead weight per unit length of the rock block B and its upper weak rock layer; h is the thickness of the basic top; l is the length of the rock block B; θ is the rotation angle of the rock block B; a is the rock block B and the rock block A, The _contact height of C; _the calculation formula a=(h-lsinθ)/2; q ₀ is the self-weight per unit length of the direct top; _A =T _B , T _A =ql/hl-12sinθ; P ₁ is the support resistance of the goaf, P ₂ is the support resistance of the working face, where the resultant force of P ₁ acts on b/2, and the resultant force of P ₂ acts on d/3; where, b and d are the width of the goaf and the supporting roof of the working face respectively;

is the friction factor between rock blocks; the length of the main wall of the cross block wall is a ₁ , the width is b ₁ , the length of the auxiliary wall is a ₂ , and the width is b ₂ ; the width of the open road is d ₁ ; e. According to the size of the cross block wall set above and the calculated distance between two adjacent cross block walls, the cross block wall is built with aerated concrete blocks for construction to support the empty alley. protect.

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